Dr. JAVIER URZAY Aerospace Engineer (CV outdated)







I left Stanford and moved as a civilian to the US Space Force in the Rocket Propulsion Division, Air Force Research Laboratory at Edwards AFB, California. I also became an Air Force reserve officer in the Space Systems Command at Los Angeles AFB, California.

This is a legacy website with archived journal papers and class notes
from my career in academia.


Fields of expertise


High-speed, chemically reacting, multi-phase flow physics
and their engineering applications to aeronautics and astronautics,
including chemical rocket propulsion, supersonic combustion,
and hypersonic aerothermodynamics of air and space flight systems.

Education


2010; Ph.D. Aerospace Engineering,
University of California San Diego (UCSD), California, USA.
Fields of study: Theoretical Combustion Physics and Fluid Mechanics.
Thesis Advisor: Prof. Forman A. Williams.

2006; M.Sc. Aerospace Engineering,
University of California San Diego (UCSD), California, USA.
Fields of study: Physical Gasdynamics and Applied Mathematics.

2005; B.Sc. + M.Sc. (Ingeniero Superior) Mechanical Engineering,
Carlos III University of Madrid, Spain.

Other training:

2022; USAF Commissioned Officer, Officer Training School (OTS)
Maxwell Air Force Base, Alabama, USA.

2019; USAF Enlisted Airman, Basic Military Training School (BMT)
Lackland Air Force Base, Texas, USA.


Media Appearances


Science documentaries:
- Seeker: "How close are we to hypersonic travel?" (video - 1 Million views);

Technical magazines and online news media:
- USAF News: "Reserve Hypersonics Bullpen Taking Air Force Higher, Further, Faster" (link).
- USAF News: "Renowned Rocket Engineer Becomes New Reserve Officer" (link).
- Stanford Engineering News: "SoE Staff spotlight series" (link).
- USAF News: "X-15 Dreams: A father's gift..." (link).
- Popular Mechanics: "60th anniversary of Yuri Gagarin's hypersonic flight" (link).
- Stanford News: "Team develops exascale computing for spaceflight" (link).
- Stanford News: "Stanford engineer's work helps propel hypersonic aircraft" (link).
- Open Mind BBVA: "Hypersonic: The Future of Aviation" (link).
- Flight Global: "3D-Printing brings scramjet engines closer to reality" (link).
- Bold Business: "Hypersonic transport and the future of commercial aviation" (link).
- Stanford News: "Stanford engineers win Gallery of Fluid Motion awards" (link).
- American Society for Engineering Education's PRISM: "Wild Blue Yonder" (link).
- The Combustion Institute: "Distinguished Paper Awarded: Turbulent Flames" (link).

Television and Radio:
- NBC TV Network: "Stanford rocket engineer becomes US Citizen" (video).
- KCBS Radio: "Stanford rocket scientist sworn in today as US Citizen" (audio).


Courses Taught


ME356 Hypersonic Aerothermodynamics (At Stanford, 2018-2021)
19 Video lectures on Hypersonics: (playlist - 40,000 views);
Instructor Notes: (PDF, 200Mb);
Student course evaluations: (PDF);


Other Courses I have taught:
ME451C Compressible Turbulence (at Stanford, 2017), Instructor Notes: (PDF, 50Mb)
ME355 Compressible Flows (at Stanford, 2016), Instructor Notes: (PDF, 100Mb)
ME471 Turbulent Combustion (at Stanford, 2012), Instructor Notes: (PDF, 44Mb)
MAE180 Spacecraft Guidance (at UCSD, 2009), Instructor Notes: (PDF, 44Mb)

Research Monographs


Jofre L. and Urzay J.,
"Transcritical diffuse-interface hydrodynamics of propellants in high-pressure combustors
of chemical propulsion systems."
Progress in Energy and Combustion Science 82, 100877 (2021). (PDF)
CTR Tea Seminar: (video);
American Physical Society -DFD presentation: (video);



Urzay J. and Di Renzo M.,
"Engineering aspects of hypersonic turbulent flows at suborbital enthalpies."
Annual Research Briefs, Center for Turbulence Research,
Stanford University, pp. 7-32 (2020). (PDF)
NASA Ames Entry Systems and Technology Division Seminar: (video)




Urzay J.,
"Supersonic combustion in air-breathing propulsion systems for hypersonic flight."
Annual Review of Fluid Mechanics 50, 593-627 (2018). (PDF)



Sánchez A.L., Urzay J. and Liñán A.,
"The role of separation of scales in the description of spray combustion"
(Invited Review Lecture at 35th International Symposium on Combustion, San Francisco CA).
Proceedings of The Combustion Institute 35, 1549-1577 (2015). (PDF)


Journal Articles


Urzay J.,
"General velocity-altitude flight-regime diagram for aeronautics and astronautics."
Journal of Spacecraft and Rockets 62, 692-695 (2025). (PDF)
High-resolution diagram: (JPG), (PDF)


Wang, J.M., Di Renzo, M., Iaccarino, G., Wang, H. and and Urzay J.,
"Laser-induced indirect ignition of non-premixed turbulent shear layers."
Combustion and Flame 264, 113426 (2024). (PDF)
(supplementary simulation videos: video A, video B, video C, video D, video E, video F)


Williams, C., Di Renzo, M., Urzay J. and Moin P.,
"Navier-Stokes characteristic boundary conditions for high-enthalpy compressible flows in thermochemical non-equilibrium."
Journal of Computational Physics 509, 113040 (2024). (PDF)


Di Renzo M. and Urzay J.,
"Direct numerical simulation of a hypersonic transitional boundary layer at suborbital enthalpies."
Journal of Fluid Mechanics 912, A29 (2021). (PDF)
NASA Ames Entry Systems and Technology Division Seminar: (video)


Huete C., Cuadra A., Vera M. and Urzay J.,
"Thermochemical effects on hypersonic shock waves interacting with weak turbulence."
Physics of Fluids 33, 086111 (2021). (PDF)
American Physical Society -DFD presentation: (PDF)


Chan W.H.R., Johnson P. E., Moin P. and Urzay J.,
"The turbulent bubble break-up cascade. Part 2. Numerical simulations of breaking waves."
Journal of Fluid Mechanics 912, A43 (2021). (PDF)


Fu L., Karp M., Bose S., Moin P. and Urzay J.,
"Shock-induced heating and transition to turbulence in a hypersonic boundary layer."
Journal of Fluid Mechanics, 909, A8 (2021). (PDF)


Di Renzo M., Fu L. and Urzay J.,
"HTR solver: An open-source exascale-oriented task-based multi-GPU high-order code for hypersonic aerothermodynamics."
Computer Physics Communications 255, 107262 (2020). (PDF); Github: (link)


Di Renzo M., Pascazio G. and Urzay J.,
"The breakdown of self-similarity in electrified counterflow diffusion flames."
Combustion and Flame 205, 231-240 (2019). (PDF)


Chan W.H.R., Mirjalili S., Jain S.S., Urzay J., Mani A. and Moin P.,
"Birth of microbubbles in turbulent breaking waves."
(paper associated with a video winner of the 2018 "APS/DFD Gallery of Fluid Motion Award'').
Physical Review Fluids 4, 100508 (2019). (PDF)


Di Renzo M., Johnson P.L., Bassenne M., Villafañe L. and Urzay J.,
"Mitigation of turbophoresis in particle-laden turbulent channel flows
by using incident electric fields."
Physical Review Fluids 4, 124303 (2019). (PDF)
(supplementary simulation video: video 1)


Bassenne M., Esmaily M., Livescu D., Moin P. and Urzay J.,
"A dynamic spectrally enriched subgrid-scale model for preferential concentration in particle-laden turbulence."
International Journal of Multiphase Flow 116, 270-280 (2019). (PDF)


Kim J., Bassenne M., Towery C.A.Z., Hamlington P.E., Poludnenko A.Y. and Urzay J.,
"Spatially localized multi-scale energy transfer in turbulent premixed combustion."
Journal of Fluid Mechanics 848, 78-116 (2018). (PDF)


Di Renzo M. and Urzay J.,
"Aerodynamic generation of electric fields in turbulence laden with charged inertial particles."
Nature Communications 9, 1676 (2018). (PDF)


Bassenne M., Moin P. and Urzay J.,
"Wavelet multiresolution analysis of particle-laden turbulence."
Physical Review Fluids 3, 084304 (2018). (PDF)


Di Renzo M., Urzay J., Di Palma P., De Tullio M.D. and Pascazio G.,
"The effects of incident electric fields on counterflow diffusion flames."
Combustion and Flame 193, 177-191 (2018). (PDF)


Yang X.I.A., Urzay J., Bose S. and Moin P.,
"Aerodynamic heating in wall-modeled large-eddy simulation of high-speed flows."
AIAA Journal 56, 731-742 (2018). (PDF)


Bassenne M., Urzay J., Schneider K. and Moin P.,
"Extraction of coherent clusters and grid adaptation in particle-laden turbulence using wavelet filters."
Physical Review Fluids 2, 054301 (2017). (PDF)


Urzay J., Doostmohammadi A. and Yeomans J.M.,
"Multi-scale statistics of turbulence motorized by active matter."
Journal of Fluid Mechanics, 822, 762-773 (2017). (PDF)


O'Brien J., Towery C.A.Z., Hamlington P.E., Ihme M., Poludnenko A.Y. and Urzay J.,
"The cross-scale physical-space transfer of kinetic energy in turbulent premixed flames."
(''Distinguished Paper Award" at the 36th International Symposium on Combustion, Seoul, Korea, 2016).
Proceedings of the Combustion Institute 36, 1967-1975 (2017). (PDF)


Park G.I., Bassenne M., Urzay J. and Moin P.,
"A simple dynamic subgrid-scale model for LES of particle-laden turbulence."
Physical Review Fluids 2, 044301 (2017). (PDF)


Towery C.A.Z., Poludnenko A.Y., Urzay J., O'Brien J., Ihme M. and Hamlington P.E.,
"Spectral kinetic-energy transfer in turbulent premixed reacting flows."
Physical Review E 93, 053115 (2016). (PDF)


Bassenne M., Urzay J., Park G.I. and Moin P.,
"Constant-energetics physical-space forcing methods for improved convergence to homogeneous-isotropic turbulence with application to particle-laden flows."
Physics of Fluids 28, 035114 (2016). (PDF)


Huete C., Urzay J., Sánchez A.L. and Williams F.A.,
"Weak-shock interactions with transonic laminar mixing layers of fuels for high-speed propulsion."
AIAA Journal 54, 966-979. (2016). (PDF)


Mortazavi M., Urzay J. and Mani A.,
"Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses."
Physics of Plasmas 22, 062122, 1-20 (2015). (PDF);
(supplementary simulation videos: video 1, video 2)


Huete C., Sánchez A.L., Williams F.A. and Urzay J.,
"Diffusion-flame ignition by shock-wave impingement on supersonic mixing layers."
Journal of Fluid Mechanics 784, 74-108 (2015). (PDF)


Liñán A., Martinez-Ruiz D., Sánchez A.L. and Urzay J.,
"Regimes of vaporization and combustion of sprays in counterflow mixing layers."
Combustion Science and Technology 187, 103-131 (2015). (PDF)


O'Brien J., Urzay J., Ihme M., Moin P. and Saghafian A.,
"Subgrid-scale backscatter in reacting and inert supersonic hydrogen-air turbulent mixing layers."
Journal of Fluid Mechanics 743, 554-584 (2014). (PDF)


Urzay J., Kseib N., Davidson D.F., Iaccarino G. and Hanson R.K.,
"Uncertainty-quantification analysis of the effects of residual impurities on hydrogen-oxygen ignition in shock tubes."
Combustion and Flame 161, 1-15 (2014). (PDF)


Timerman D., Greene D.F., Urzay J. and Ackerman J.D.,
"Turbulence-driven resonant vibrations cause pollen release in wind pollinated Plantago Lanceolata L."
Journal of the Royal Society Interface 11, 20140866 (2014). (PDF);
(supplementary experimental videos: video 1)


Martinez-Ruiz D., Urzay J., Sánchez A.L., Liñán A. and Williams F.A.,
"Dynamics of thermal ignition of spray flames in mixing layers."
Journal of Fluid Mechanics 734, 387-423 (2013). (PDF)


Urzay J., Nayagam V. and Williams F.A.,
"Theory of the propagation dynamics of spiral edges of diffusion flames in von Kármán swirling flows."
Combustion and Flame 158, 255-272 (2011). (PDF);
(supplementary experimental videos: video 1, video 2, video 3, video 4)


Urzay J.,
"Asymptotic theory of the elastohydrodynamic adhesion and gliding motion of a solid particle over soft and sticky substrates at low Reynolds numbers."
Journal of Fluid Mechanics 653, 391-429 (2010). (PDF)


Urzay J., Llewellyn Smith S., Thompson E., and Glover B.J.,
''Wind gusts and plant aeroelasticity effects on the aerodynamics of pollen shedding: A hypothetical turbulence-initiatied wind-pollination mechanism."
Journal of Theoretical Biology 259, 785-792 (2009). (PDF)


Urzay J., Nayagam V. and Williams F.A.,
"Diffusion-flame extinction on a rotating porous-disk burner."
Proceedings of the Combustion Institute 32, 1219-1226 (2008). (PDF)


Urzay J., Llewellyn Smith S. and Glover B.J.,
"The elastohydrodynamic force on a sphere near a soft wall."
Physics of Fluids 17, 103106, 1-7 (2007). (PDF)


Technical Reports (selected)


Williams C., Di Renzo M. and Urzay J.,
"Two-temperature extension of the HTR solver for hypersonic turbulent flows in thermochemical nonequilibrium."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2021),
pp. 95-107. (PDF)


Williams C., Di Renzo M., Moin P. and Urzay J.,
"Locally self-similar formulation for hypersonic laminar boundary layers in thermochemical nonequilibrium."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2021),
pp. 119-128. (PDF)


Wang J., Di Renzo M., C. Williams, Urzay J. and Iaccarino G.,
"Progress on laser ignition simulations of a CH4/O2 subscale rocket combustor using a multi-GPU task-based solver."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2021),
pp. 129-142. (PDF)


Jofre L. and Urzay J.,
"A characteristic length scale for density gradients in supercritical monocomponent flows
near pseudoboiling."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2020),
pp. 275-280. (PDF)


Di Renzo M. and Urzay J.,
"An a-priori study of the accuracy of an equilibrium wall model
for dissociating air in supersonic channel flows."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2019),
pp. 29-40. (PDF)


Chan W.H.R., Urzay J. and Moin P.,
"Subgrid-scale modeling for microbubble generation amid colliding water surfaces."
In Proceedings of the 32nd Symposium on Naval Hydrodynamics,
Hamburg, Germany (2018). (PDF)


Urzay J., Bassenne M., Park G.I. and Moin P.,
"Characteristic regimes of subgrid-scale coupling in LES of particle-laden turbulent flows."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2014),
pp. 3-13. (PDF)


O'Brien J., Urzay J., Poludnenko A.Y., Hamlington P.E. and Ihme M.,
''Counter-gradient subgrid-scale transport and reverse-cascade phenomena in turbulent deflagrations.''
Proceedings of the Summer Program, Center for Turbulence Research, Stanford University (2014), pp. 147-157. (PDF)


Urzay J., Kseib N., Palacios F., Larsson J. and Iaccarino G.,
"A stochastic flamelet progress-variable approach for numerical simulations of high-speed turbulent combustion under chemical-kinetic uncertainties."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2012),
pp. 17-30. (PDF)


Urzay J., Kseib N., Costantine P.G., Davidson D.F. and Iaccarino G.,
"Uncertainty-quantifying models for chemical-kinetic rates."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2012).
pp. 3-16. (PDF)


Urzay J.,
''A revised spray-combustion diagram of diffusion-controlled burning regimes in fuel-spray clouds."
Annual Research Briefs, Center for Turbulence Research, Stanford University (2011),
pp. 193-198. (PDF)


Other Work


Urzay J.,
"The physical characteristics of hypersonic flows."
In ME356 Hypersonic Aerothermodynamics class notes.
Center for Turbulence Research, Stanford University (2020). (PDF)




Chan W.H.R., Mirjalili S., Jain S., Urzay J., Mani A. and Moin P.,
"Birth of microbubbles in turbulent breaking waves."
APS Gallery of Fluid Motion Award Winner,
(link to video entry at Gallery of Fluid Motion)
71st annual meeting, American Physical Society, Division of Fluid Dynamics, Atlanta GA (2018).


Urzay J., Ott D.W. and Prakash M.,
"The unique low-Reynolds spinning hydrodynamics of release of a multinucleate multiflagellate giant zoospore."
(link to video entry at Gallery of Fluid Motion)
67th annual meeting, American Physical Society, Division of Fluid Dynamics, San Francisco CA (2014).

Theses


Ph.D. Thesis: Urzay J., "Theoretical studies on spiral edge-flame propagation and particle hydrodynamics".
Department of Mechanical and Aerospace Engineering, University of California San Diego, USA (2010). (PDF)

B.Sc./M.Sc. Thesis: Urzay J., "Fluidodinamica de chorros laminares ligeros" (in spanish).
Department of Thermal Engineering and Fluid Mechanics, Carlos III University of Madrid, Spain (2005). (PDF)



Contact Information